Control mechanism



Dec. 24, 1946. c. H. DEDERICK 2,413,137

CONTROL MECHANISM 2 Sheets-Sheet 1 Filed June 21 1943 LIMIT SWITCH WW 3... gw;

H. DEDERECK CONTROL MECHANI SM Filed June 21, 19 .3 2 Sheebs-Shee'i; 2

Patented Dec. 24 1946 UNITED STATES PATENT OFFICE (JONTROL MECHANISM Clinton H. Dedericlr, Brentwood, Mo., assignor to The Emerson Electric M fg. Company, St. Louis, a corporation of Missouri Application June 21, 1943, Serial No. 491,583

14 Claims. 1

The present invention relates to a control mechanism. More particularly, it is directed to control mechanism for accurately producing redetermined movement of a motor and some object displaced by the motor.

The invention is related to Serial No. 483,993, filed by the same inventor on April 21, 1943.

It is an object of this invention to provide a control that will produce precisely a predetermined amount of movement of the motor, and then stop. More particularly, it is an object to accomplish this through the use of selectable circuits in combination with slip ring mechanism that causes the circuits to be energized and step ping magnets energized a number of times determined by the number of rotations of the motor for operating the slip ring mechanism to neutral position.

A further object to provide a mechanism of this kind which will cause the motor to start operating immediately upon commencement of the stepping operation and to continue operating until it has operated a number of times determined by the position of the control upon completion of the setting operation.

A further object of the invention is to provide a c ntrol of this type having a dial and pointer means cooperating with the dial to indicate both the desired setting of the mechanism driven by the motor and also at all times to indicate the actual position of that mechanism.

A further object of the invention is to provide a control of this type which will insure operation of the control to a full neutral position.

A. further object is to provide a control of this type for use with a motor having limit switches preventing excess travel of the motor and adapted to open the circuits thereof upon such excess travel, stepping magnets in the control operated by breaker points opened and closed by the motor, with means to effect a restart of the motor in the other direction, if a limit switch open when the breaker points are closed.

In the drawings:

Fig. l is a wire diagram of the control;

Fig. 2 is a front view of the dial and snob;

Fig. 3 is a section through the dial and knob part of the control taken on the line L--3 of Fig. 2;

Fig. Q is apartial view of one of the stepping magnets and its relay switches;

Fig. 5 is a iragmental section of the switch taken-on the line 5-45 of Fig. 4, and

Fig. 6 is a schematic view of a modification of the circuit.

Referring to Fig. i, it may be seen that the control comprises a slip ring operator is, power relays, stepping magnets and relays, a motor generally indicated at l l, and a breaker switch 12.

The motor construction is that disclosed in the copending application previously referred to. This motor may be used as a position means as, for instance, to position trimmer tabs on aircraft wings. The actuated mechanism has been symbolically here represented at M. Oscillation of the motor shaft will displace the member M up or down.

Diagrammatically, the slip ring mechanism comprises two substantially semi-circular outer segments 29 and 2!. These segments are adapted to be wiped by a contact arm 22, electrically con nected with an inside ring 23. A larger medium sized ring 24 i electrically connected at 25 with the segment 28. A smaller inside ring 25 is electrically connected at 2'1 with a segment 2!.

A wiper 28 is constantly engaged with the inside ring 23, and is connected by a line 29a. to a power line 29. The ring 2G is connected by a wiper 30 to a line 3i. The ring 25 has a wiper 32 that is connected to a line 33.

It will be seen from the foregoing that power is always connected to the wiper arm 22. When the ring disc is moved in one direction or the other, it will cause the wiper arm to contact either the segment 2a or the segment 21. If the direction of rotation connects the wiper 22 with the segment 29, then the line 3! will be connected to power; whereas if the rotation is in the other direction, the line 33 will be connected to power.

The line 3i leads to a contact s5 which closes with a. contact 3; on a switch 3'. of a stepping magnet and relay 38 when the latter is deenergized. The contact 36 is in turn connected by a line 39 to one end of a coil as of a power relay ll. The other end of this coil is connected by a line 42 to a line 43, and through a manual switch 44 to ground.

The other line 33 is connected to a contact 45 which closes with a contact 46 on the relay.

switch 4! on another stepping magnet and relay 28, when that relay is deenergized. The contact 36 of the switch 41 is connected by a line is to one end of a coil to of another power relay 5!. The other end of the coil 59 is connected by a line 52 to the line Q3, and thence through the switch 44 to ground.

The power line 29 has an additional branch 29b. This branch ultimately leads through the shunt coil 55 of the motor H, and thence to ground,

thus maintaining the field of the motor constantly energized to act as a dynamic brake, as will appear. The line 251) also branches at 290, which ultimately leads to a normally open contact 56 on the switch 51. The line 250 likewise is connected with contacts 5'5 and 58 that are parts of the power relay 4!, and contacts 55 and 5!; that are parts of the relay 5!, Also, a line 29d connects line 291) with a contact ti on the switch 37, corresponding to the contact 55 on the switch 41.

The contact 55 on the switch il of the magnet 48 is adapted to close with a contact 53 that is connected by a line 63 with the line 35, when the magnet is energized. Similarly, the contact M of the switch 3'1 is adapted to close with a contact 55 that is connected by a line 56 with the line 39.

The contact 5'! of the power relay ll is adapted to close with a double contact 68 on that relay switch, when the relay is energized. The contact 68 is connected by a line it that leads to one of the limit switches of the motor. The contact 68 in its lower position is adapted to close with a contact ll that is connected by line '82 to ground. The contact 58, connected with the line 290, is adapted to be closed with a contact M on the power relay 4!, when it is energized. Contact M is connected by a line l5 into the coil it of the stepping magnet 48. The other end of this coil is connected by line ll through the switch E2, to ground.

The contact 55, connected to the line 290, is-

adapted to close with the contact '25 on the relay switch 5i, when the relay is energized. The contact i8 is connected by a line l9 into the relay coil 80 of the magnet 35, the other end of which is connected with the line 1?.

The contact 55 of the power relay 5i is adapted to close with the double contact 82 that is connected by a line 33 to the other limit switch on the motor. The contact 32 is likewise adapted to close with a contact 3 1 that is connected to the line l2 and thence to ground.

The motor ll includes a rotor 90. One of the brushes of the rotor is connected by a line ill with a movable contact 92 of the limit switch 93. The contact 92 normally closes with a con tact as connected to the line it. Upon excess travel of the motor in one direction the contact 92 is shifted to close with a contact 85 connected by a line 93 to ground.

The other brush in the motor is connected by a line 5? to a movable contact 98 of a limit switch 539. Normally the contact 98 is closed with a contact Ito connected to the line 83. Upon excess movement of the motor in the direction opposite that previously mentioned, the movable contact 98 will be shifted to close with a contact ltl connected, in turn, with the line 95 and ground.

Details of the motor and the limit switches and the switches i2, are set forth in the co-pending application referred to.

The stepping magnet construction is basically the same as that set forth in the co-pending application referred to, and consists of a toothed wheel attached to a shaft, with magnetic armature arms extending across the top edge of the wheel on opposite sides of a diameter thereof. When either magnet is energized it will draw its arm down against the wheel and move it in a corresponding direction the space of one notch or tooth On the wheel.

Figs. 2-5 show the details of the control mechanism necessary to understand the difierences of the present application over the co-pending one. In Figs.2 and 3 a mounting plate Hi3 has screw holes by means of which it may be attached to the instrument panel or other suitable support. The mounting plate H0 has a cylindrical flange ill extending outwardly from the face thereof. This flange is provided with a dial H2. It provides a cup-shaped recess into which is mounted a cup-shaped pointer member H3, having an index as shown in Fig. 2, preferably formed by coloring one half of the disc black. The member i 83 has an extending hub Ht bearing in a cylindrical opening through the mounting member i iii and rotatable therein. The hub H4 opposite the mounting member HI supports a slip ring disc H5 which contains the two segments 20 and 2 I, and the slip rings 2 and 26. The brushes for these rings 2:; and 26 are shown in contact with the rings as indicated. The hub El i also supports a toothed wheel H5 that is engaged by a spring urged roller R to hold the member H3 and attached elements in position against fortuitous movement.

The outer portion of the cup-shaped member H3 is covered by a transparent plastic disc Ill to which is attached a knob H8. It will be seen that rotating the knob I I3 turns the cup-shaped member i it and with it the slip ring disc H5.

The hub iii of the cup-shaped member H3 receives a main shaft i263 which extends rotatably through the hub H4 and has at its outer end an indicating disc l2! disposed beneath the transparent element ill. The indicating disc iZl provides a movable pointer 122 preferably emphasized by coloring one half of the disc black.

The shaft I20 likewise has secured thereto the contact or wiper arm 22 heretofore described. This wiper arm is caused to move when the shaft moves, by being secured to disc I23 having the slip ring 23 formed thereon, and engaged by the wiper 28.

The stepping magnet construction for moving the shaft lZil includes a toothed wheel I25, the same as that in the aforesaid co-pending application. This wheel is adapted to be engaged on its upper edge on opposite sides of the vertical by two stepping magnet arms, one of which is shown at I26 in Fig. 3, and the other of which is shown at I2? in Fig. i.

The arms 525 and HT are parts of armature constructions for the stepping relays 38 and t8.

These two relays are of similar construction so that only one need be described. With the exception of the switch connections, these relays are identical in construction with those in the co-pending application.

The relay coil '15 is mounted on a bracket I38 secured to a wall I59 on the housing of the mechanism. The bracket 138 has an upstanding portion receiving an armature plate It! ivoted thereon. A coil spring I32 is attached between a tail and the bracket I35 and an arm on the armature plate It! to urge the plate upwardly and to maintain the arm I21, which is secured to the plate I31, away from the wheel l25.

The armature i3| actuates the switch 41.

A switch bar l33'overlies the arm I21 and is riveted to the arm 53 I, (Fig. 5) retaining the arm I21 therebetween. The bar I33 has the double contacts 26 and 56 thereon. When the coil 16 is not energized the spring l32 urges the armature l3! up, which brings the contact 46 against the fixed terminal 45, thereby establishing a circuit between them.

When the coil is energized the contact 56 is brought against the fixed contact 63. These actions occur coincidentally with the operation of the ratchet mechanism. Of course, this switch construction is merely typical as it is well known in the art how such mechanisms are constructed. It may be remarked that the contacts 46 and 5B are insulated from the switch bar I33.

In Fig. 1 there is shown a manual switch 44 for a purpose to be described. A modification, shown in Fig. 6, avoids the necessity of using this switch, and provides an automatic means to perform its functions.

In Eig. 6 a relay switch I40 is employed with its coil I 4| in parallel with the rotor 90 of the motorI I. The coil controls a switch element I42 interposed in the line leading from the switch I2 to ground. The relay closes the switch I42 only when the rotor circuit is closed and the coil I4I energized. Otherwise the relay drops out, and breaks the circuits through the switch I2.

Operation If this control and motor mechanism is to be used, for example, to set trimmer tabs on an airplane, it will be assumed that when the arm 22 is in the starting position shown in Fig. 1, and the dial in corresponding position as shown in Fig. 2, the tabs are in neutral position. In this starting position the arm 22 is between the segments 20 and 2I, the field coil 55 is energized, and both ends of the rotor circuit are grounded, so that the motor windings can act as a brake on the motor.

By the present mechanism these tabs may be displaced'upwardly or downwardly as desired. Assume that it is desired to set the trimmer tab upwardly to an angle of The operator will turn the knob I I8, carrying with it the cup member I I3 until the index thereon registers with the 10 up graduation, on the dial II2. This manual displacement of the member II3 does not change the position of the shaft I20 or the indicating disc I2I attached thereto. This movement is in the direction of the arrow shown in Fig. 1.

The attachment of the slip ring disc I I 5 to the hub of the cup member H3 causes the slip ring disc I I5 to be moved to bring the segment 20 into contact with the contact wiper of the arm I 22. Referring more particularly to Fig, 1, this will connect the power line 29a to the segment 20 and to the inner ring 24 from whence current flows through the line 3|, to the contact 35 of the stepped magnet relay 38. Since the magnet at this time is not energized, the contact 36 is closed with contact 35 and the current, therefore, continues through the line 39 through the power relay coil 49, to line 42, to line-43, to manual switch 44, to ground. This causes the powerrelay 4| to lift, which causes the switch contacts 51 and 58 to close with the contacts 68 and I4 respectively, introducing power from the line 290 to these latter contacts. Power thus is introduced from the line 290 through contacts 51 and 68, line III, limit switch contacts 94 and 92, line 9|, rotor 99, line 91, limit switch contacts 98 and [III], line 83, contacts 82 and 84 and line 72 to ground. Current flowing through this circuit starts the rotor in one direction, as the field coil 55 is constantly in circuit. The motor shaft,

through the reduction gearing G, operates the trimmer mechanism toward the selected position and starts rotation of the cam of switch I2.

At the same time as the foregoing motor cir- 6 cuit is closed, power flows from the line 290 through the contacts 58 and I4, to line 15, to stepping magnet relay coil I6, line 11, to the switch I2, and when the switch I2 is closed, the circuit will be completed through said switch to ground, energizing the coil 16.

The coil "I6 breaks the contacts 46 and 45, which has no. effect at this time. It also closes the contacts 55 and 63, which gives a power connection from the line 290 through the switch contacts and the line I54 to the line 39 thus shunting the slip ring switch II) and the switch 31 whenever the coil 16 is energized to close the contacts 55 and 63.

At the same time as the switch 41 is operated, the arm I26 will be drawn down to strike the toothed wheel I25 and displace it the space of one tooth. This will cause the shaft I20 to be rotated corres onding distance toward the previously made 10 selection, so that its indicating disc I2I registers one graduation to the right of zero on the dial II2.

It will be observed that the power relay coil 40 is held in circuit whenever the segment 20 is in contact with the arm 22 and the coil of the stepping magnet 38 is not energized. The motor circuit is established through this circuit. It will be further observed, however, that the stepping magnet coil 76 is de-energized whenever the switch I2 breaks. Therefore, the coil I6 is given a number of impulses for any given number of rotations Off the armature of the motor. Furthermore, each impulse steps the shaft I 2% its pointer disc I2I, and the slip ring disc H5, toward the pre-set position of the cup II3. The number of rotations of the motor and the number of steps of the pointer I2I are directly proportionate.

When the contact arm 22 is moved to the starting end of the segment 28, it will drop off of the end thereof. In order to complete the impulse despite breaking of the circuit through the slip ring, and to insure clearance of the arm 22 from the segment 29, the coil '56 will be maintained operative by the power relay 4I through the circuit closed by the contacts 55 and 63, which establish the aforementioned circuit that shunts the slip ring switches at the time the coil I6 is energized. This circuit holds until the motor opens switch I2, at which time the shunt circuit through contacts 55 and 63 is broken and both control and motor circuits are opened. By this shunt circuit a complete operation of the stepping magnet is assured, and the motor and control stop at the point where the arm 22 is disposed between the segments 20 and 2|. The pointer will at such time coincide with the chosen graduation on the dial.

At this point the control is in neutral position but with both pointers registering 10 on the dial. The motor will have rotated a predetermined number of revolutions which are the number required to move the trimmer tab 10 upwardly. The circuits of the control will be opened, but the circuit from the line 2917 through the field winding 55 of the motor will stay closed. The armature circuit will be grounded at both ends as at the start. Consequently, the winding 55 Will act as a dynamic brake to stop the motor at once, and prevent any override of the trimmer tab.

From this 10 position the knob may be operated either upward or downward as desired. If turned upward it will reestablish the circuit previously mentioned until the tab and the control attain the advance positions selected. If turned 7 downwardly corresponding circuits on the other side of the control will be established, which are in every way symmetrical with the circuits described, and which send the current through the rotor in the other direction.

If the operator desires, he may change the setting of the control during the time it is stepping toward a previous setting. If this change is wholly above the point to which the control has already stepped, it will have no effect on the circuits other than to change the point at which they will ultimately open. If the change is sufficiently far in the opposite direction to that previously selected to cross over the position to which the control and the motor have advanced toward the earlier setting, then if the slip ring disc is moved so that it brings the break between the segments 23 and 2! to the arm 22 at the time the.

switch I2 is instantaneously open and the stepping magnet coil 38 released, the power relay 50 will immediately drop out. This will at once ground both sides of the armature motor and stop it. A quick passage of the slip ring disc to bring the opposite segment 2! under the arm 22 will energize the power relay i? which is dependent only upon closing of the segment 2| with the arm 22 and release of the stepping magnet coil 16. This will close the other motor circuit through the contacts 68 and 82, and will close the other stepping magnet coil circuit through contacts 59 and 18 down to the switch :2. This switch will be closed as soon as the motor, operating in its new direction, can rotate the cam. The device will thereupon begin to step backward with the motor continuing to rotate in the other direction until the control reaches the new selected position.

It will be observed that this new position may be merely a reduction in the angularity of the trimmer tab in its previous direction, or it may be a reversal of the angularity of the trimmer tab, depending upon whether the knob is turned across the zero point on the dial or not. In other words, any stepping back of the control is the same in function whether the control starts from zero position and moves in a given direction, or starts from a previously advanced position and moves in the opposite direction.

If, in a reversal of the knob during a setting operation, the neutral position between the segments 20 and 2| is reached at the time the switch I2 is closed, to produce an impulse tending to advance the control in the direction from which it is being reversed, the holding circuit through the contacts 56 and 63 will keep the power relay coil Mi in circuit until the stepping operation is complete. The motor will be held in circuit because the power relay is held, until the completion of the stepping operation and breaking of the switch 52 to release coil 76. Hence the indicator I22 and the motor continue their corresponding movement in the original direction, and the indicator shows accurately the position of the motor.

However, if the swing-over from the segment 2%! to the segment 2! is made so fast that the segment 2! is put in circuit before the cleanup operation of the stepping magnet 48, the circuit to the other power relay 50 cannot be made because it is dependent upon a release of the coil 75 to close the contacts and lG. Therefore, the

.then operating motor circuit which passes through the contacts 82 and B4, and therefore is dependent upon deenergization of the coil 40, is not broken. Thus the motor,the shaft I20 with its wiper arm 22, and indicating disc IZI, will move together until the completion of the stepping operation, followed by release of the coil 16, and the indicator will always show the exact 5 position of the trimmer tab at any time despite any change in the setting of the control in the middle of an operation. As soon as the cleanup operation is completed, and coil 16 is released, the switch 41 closes contacts 46 and 45, completing the circuit to the other power relay 56, and the backward operation can begin.

If the motor is caused to move an excessive distance in any direction, it will shift the limit switch in that direction as set forth in the co-pending application. Thus, if a setting of the control as heretofore, in a direction to bring segment 20 under the arm 22, is excessive, then after a predetermined number of revolutions of the motor the contact 92 of the limit switch 93 will move from the contact 9 3 to the contact 95. This will break the power input to the rotor and will connect both ends of the rotor circuit to ground. For example, this will pass from ground through the line 96, contacts 95 and 92, line 9!, rotor 98, line Bl, contacts 98 and IE0, line 83, contacts 82 and 84, and line 12 to ground. This will produce the dynamic braking efiect to stop the motor immediately.

If this braking occurs when the switch I2 is closed, the power relay 4| will stay energized, holding the stepping magnet 48 up, through the contacts 56 and 63, thus preventing release of these circuits even when the segment 20 is moved from the arm 22, and the segment 22 is put thereunder. The circuit to the other power relay 5! cannot close, because of separation of the contacts 55 and 46, so that the mechanism remains locked. To release it, the operator opens manual switch Mi, which releases the power coil GB and the stepping coil l6, breaking the holding circuits thereof. Upon subsequent reclosing of the switch as, the power coil 50 will be energized and the other side of the control operated to step the device back. a

It will be understood that the other limit switch 99 functions in like manner.

When the auxiliary relay Hit! of Fig. 6 is used, the release above is effected automatically. In this case the closure of the stepping magnet cir- 50 cuits is dependent upon energization of oneof the motor circuits, as the coil iii is in parallel with the rotor. Hence, if the operation of a limit switch opens a rotor circuit, the stepping magnet circuit opens, and upon resetting of the control onto the other segment, the opposite rotor circuit is closed. When magnet Hit is deenergized due to both ends of coil being connected to ground, the switch M2 isopened, which breaks the circuit to the stepping relay coil. Switch 41 69 then closes points it and ifi completing the circuit to power relay coil 50 when the control is turned for opposite rotation.

For example, if the motor circuit opens by the limit switch 53. grounding at 95, then the coil it of the stepping magnet to is deenergized by the opening of the switch M2, thus releasing the holding circuit for the power relay 60. At thistime both ends of the rotor are grounded.

Thereafter, when the segment 2| is displaced 70 under the arm 22, the power relay 5B is put in circuit, which lifts the contact 82 from the grounded contact 84 to the hot contact 60. This then establishes a reversing rotor circuit that grounds through line 96. And of course the establishment of the new rotor circuit reenergizes the auxiliary vrelay will step back Mil, so that the control in proportion to the number of revolutions of the motor, or more exactly, the number of operations of the switch 22. As soon as the rotor reverses sufliciently to permit the snap limit switch 93 to return the contact to the contact 94, the grounding of the new rotor circuit is effected through the new grounded contact 63 of the other power relay.

What is claimed is:

1. In a mechanism of the kind described, a motor and a control for causing a predetermined number of revolutions of the motor, said control including a pre-set device and a follower device, said devices being adapted to be r a neutral relative position, the pro-set device being adapted to be operated to establish circuits and the follower device being adapted to be moved from neutral position to a position to break said circuits, a first circuit through the pre-set device in operated position to operate the motor, a second circuit contr lled by the -re-set device, operating means for the follower device to displace the same toward position to break the ci cuits a predetermined degree upon each energization thereof, a motor switch means made and broken in a cycle a predetermined number of times for each revolution of the motor, said second circuit including the operating means and the motor switch means whereby upon operation of the pre-set device the motor will start, and the follower device will be moved toward circuit breaking condition, and break the circuits after a predetermined nun, .cr of revolutions of the motor, said operating means for the follower device including a switch closed upon operation thereof, and a shunt circuit through said switch to maintain the first and second circuits closed regardless of the pre-set device as long as said operating means is operated.

2. In a mechanism of the kind described, a motor and a control for causing a predetermined number of revolutions of the motor, said control including a pre-set device and a follower device, said devices being adapted to be in a neutral relative position, the pro-set device being adapted to be operated to establish cir nits and the follower device being adapted to be moved from neutral position to a position to break said circuits, a first circuit, said first circuit including a single relay and switches automatically controlled thereby, one of said switches being adapted to close a motor circuit whereby the motor may operate when the relay is energized, a second circuit including another of said relay switches which is closed when the relay is energized, operating means for the follower device to displace the same toward position to break the circuits a predetermined degree upon each energization thereof, a motor switch means made and broken in a cycle a predetermined number of times for each revolution of the motor, said second circuit including the operating means and the motor switch means, whereby upon operation of the pro-set device the motor will start, and the fol.- lower device will be moved toward circuit breaking condition, and will break the circuits after a predetermined number of revolutions of the motor.

3. In a mechanism of the kind described, a motor and a control for causing a predetermined number of revolutions of the motor, said control including a pre-set device and a follower device, said devices being adapted to be in a neutral relative position, the pre-set device beingadapted to be operated to establish circuits and the follower device being adapted to be moved from neutral position to a position to break said circuits, a first circuit, said first circuit including a relay and switches operated thereby, one of said switches being adapted to close a motor circuit whereby the motor may operate, second circuit including another of said relay switches, operating means for the follower device to displace the same toward position to break the circuits a predetermined degree upon each energization thereof, a motor switch means made and broken in a cycle a predetermined number of times for each revolution of the motor, said second circuit including the operating means and the motor switch means, whereby upon operation of the pro-set device the motor will start, and the follower will be moved toward circuit breaking condition, will break the circuits after a predetermined number of revolutions of the motor, said pe-set device and follower device comprising a wiper means and slip ring means, adapted to be disengaged in neutral position, one of which means is displaceable from neutral position a selectable distance and in such displacement brought into contact with the other, and the other being adapted to be displaced in contact with the one until it reaches the neutral position thereon.

i. In a mechanism of the kind described, a reversible motor, circuit therefor, and a control for causing a predetermined number of revolutions of the motor in either direction, said control including a pre-set device and a follower device, said devices being adapted to be in neutral relative position, the pre-set device being adapted to be operated to establish a forward set of circuits and a reverse set of circuits, and the follower device being adapted to be moved upon establishment of one of said circuits a distance from neutral position sufiicient to break the circuit and reestablish neutral conditions, the setting of the pre-set device in either direction determining the distance of movement of the follower device in that direction required to break the circuits, a forward first circuit through the pro-set device set in one direction to cause operation of the motor in a forward direction, a reverse first circuit through the pre-set device set in the other direction to cause operation of the motor in the other direction, each of said circuits including a relay automatically energized by the setting of the pre-set device to close the proper motor circuit, forward operating means to operate the follower device to displace the same in forward direction toward position to break the circuits, reverse operating means to operate the follower device to displace the same in reverse direction toward position to break the circuits, a motor'switch means made and broken in a cycle a predetermined number of times per revolution of the motor, a second forward circuit controlled by the relay of the first forward circuit and including the forward operating means and the motor switch, and a second reverse circuit controllcd by the relay of the reverse first circuit and including the reverse operating means and the motor switch, whereby upon operation of the pre-set device in either direction the motor will start in a corresponding direction, and the follower device will be successively moved toward circuit breaking condition a predetermined degree per each revolution of the motor.

5. In a mechanism of the kind described, a reversible motor and a control for causing a predetermined number of revolutions of the motor in either direction, said control including a preset device and a follower, said devices being adapted to be in neutral relative position, the pre-set device being adapted to be operated to establish a forward set of circuits and a reverse set of circuits, and the follower device being adapted to be moved upon establishment of one of said circuits a distance from neutral position sufficient to break the circuit and reestablish neutral conditions, the setting of the pre-set device in either direction determining the distance of movement of the follower device in that direction required to break the circuits, a forward first circuit through the pre-set device set in one direction to cause operation of the motor in a forward direction, a reverse first circuit through the pre-set device set in the other direction to cause operation of the motor in the other direction, forward operating means to operate the follower device to displace the same in forward direction toward position to break the circuits, reverse operating means to operate the follower device to displace the same in reverse direction toward position to break the circuits, a motor switch means made and broken in a cycle a predetermined number of times per revolution of the motor, a second forward circuit controlled by the first forward circuit and including the forward operating means and the motor switch, and a second reverse circuit controlled by the reverse first circuit and including the reverse operating means and the motor switch, whereby upon operation of the pro-set device in either direction the motor will start in a corresponding direction, and the follower will be successively moved toward circuit breaking condition a predetermined degree for each revolution of the motor, and means on each operating means adapted to close the other first circuit only when said operating means is inoperative.

6. In a mechanism of the kind described, a reversible motor and a control for causing a predetermined number of revolutions of the motor in either direction, said control including a preset device and a follower, said devices being adapted to be in neutral relative position, the pre-set device being adapted to be operated to establish a forward set of circuits and a reverse set of circuits, and the follower device being adapted to be moved upon establishment of one of said circuits a distance from neutral position sufiicient to break the circuit and reestablish neutral conditions, the setting of the pre-set device in either direction determining the distance of movement of the follower device in that direction required to break the circuits, a forward first circuit through the pre-set device set in one direction to cause operation of the motor in a forward direction, a reverse first circuit through the pre-set device set in the other direction to cause operation of the motor in the other direction, forward operating means to operate the follower device to displace the same in forward direction toward position to break the circuits, reverse operating means to operate the follower device to displace the same in reverse direction toward position to break the circuits, a motor switch means made and broken in a cycle a predetermined number of times per revolution of the motor, a second forward circuit controlled by the first forward circuit and including the forward operating means and the motor switch, and a second reverse circuit controlled by the reverse first circuit and including the reverse operating means and the motor switch, whereby upon operation of the pre-set device in either direction the motor will start in a corresponding direction, and the follower will be successively moved toward circuit breaking condition a predetermined degree for each revolution of the motor, and means to prevent closure of one first circuit when the other operating means is in operated position, said means having an element movable with said operating means.

7. In a mechanism of the kind described, a reversible motor and a control for causing a predetermined number of revolutions of the motor in either direction, said control including a pre- Set device and a follower, said devices being adapted to be in neutral relative position, the pro-set device being adapted to be operated to establish a forward set of circuits and a reverse set of circuits, and the follower device being adapted to be moved upon establishment of one of said circuits a distance from neutral position suficient to break the circuit and reestablish neutral conditions, the setting of the pre-set device in either direction determining the distance of movement of the follower device in that direction required to break the circuits, a forward first circuit through the pre-set device set in one direction to cause operation of the motor in a forward direction, a reverse first circuit through the pro-set device set in the other direction to cause operation of the motor in the other direction, forward operating means to operate the follower device to displace the same in forward direction toward position to break the circuits, reverse operating means to operate the follower device to displace the same in reverse direction toward position to break the circuits, a motor switch means made and broken in a cycle a predetermined number of times per revolution of the motor, a second forward circuit controlled by the first forward circuit and including the forward operating means nd the motor switch, and a second reverse circuit controlled by the reverse first circuit and including the reverse operating means and the motor switch, whereby upon operation of the pre-set device in either direction the motor will start in a corresponding direction, and the follower will be successively moved toward circuit breaking condition a predetermined degree for each revolution of the motor, and means comprising control means on each operating means to shunt the pre-set device in the corresponding first circuit when the corresponding operating means is in operated position.

8. In a mechanism of the kind described, a reversible motor and a control for causing a predetermined number of revolutions of the motor in either direction, said control including a preset device and a follower, said devices being adapted to be in neutral relative position, the pre-set device being adapted to be operated to establish a forward set of circuits and a reverse set of circuits, and the follower device being adapted to be moved upon establishment of one of said circuits a distance from neutral position sufficient to break the circuit and reestablish neutral conditions, the setting of the pre-set device in either direction determining the distance of movement of the follower device in that direction required to break the circuits, a forward first circuit through the pre-set device set in one direction to cause operation of the motor in a forward direction, a reverse first circuit through the pre-set device set in the other direction'to cause operation of the motor in the other direction, forward operating means to operate the follower device to displace the same in forward direction toward position to'break the circuits, reverse operating means to operate the follower device to displace the same in reverse direction toward position to break the circuits, a motor switch means made and broken in a cycle a predetermined number of times per revolution of the motor, a second forward circuit controlled by the first forward circuit and including the forward operating means and the motor switch, and a second reverse circuit controlled by the reverse first circuit and including the reverse operatin means and the motor switch, whereby upon operation of the pre-set device in either direction the motor will start in a corresponding direction, and the follower will be successively moved toward circuit breaking condition a predetermined degree for each revolution of the motor, means on each operating means to shunt the pre-set device in the corresponding first circuit when the corresponding operating means is in operated position, and means to prevent closure of one first circuit when the other operating means is in operated position.

9. In a mechanism of the kind described, a reversible motor and a control for causing a predetermined number of revolutions of the mo tor in either direction, said control including a pre-set device and a follower, said devices being adapted to be in neutral relative position, the pre-set device being adapted to be operated to establish a forward set of circuits and a reverse set of circuits, and the follower device being adapted to be moved upon establishment of one of said circuits a distance from neutral position suflicient to break the circuit and reestablish neutral conditions, the setting of the pre-set device in either direction determining the distance of movement of the follower device in that direction required to break the circuits, a forward first circuit through the pre-set device set in one direction to cause operation of the motor in a forward direction, a reverse first circuit through the pro-set device set in the other direction to cause operation of the motor in the other direction, forward operating means to operate the follower device to displace the same in forward direction toward position to break the circuits, reverse operating means to operate the follower device to displace the same in reverse direction toward position to break the circuits, a motor switch means made and broken in a cycle a predetermined number of times per revolution of the motor, a second forward circuit controlled by the first forward circuit and including the forward operating means and the motor switch, and a second reverse circuit controlled by the reverse first circuit and including the reverse operating means and the motor switch, whereby upon operation of the pro-set device in either direction the motor will start in a corresponding dir ction, and the follower will be successively moved toward circuit breaking condition a predetermined degree for each revolution of the motor, means on each operating means to shunt the pre-set de vice in the corresponding first circuit when the corresponding operating means is in operated position, and means to prevent closure of one first circuit when the other operating means is in operated position, and means to release the operated means from operated position when the motor circuit is opened.

10. In a mechanism of the kind described, a re versible motor and a control for causing a pre- M determined number of revolutions of the motor in either direction, said control including a preset device and a follower, said devices being adapted to be in neutral relative position, the preset device being adapted to be operated to establish a forward set of circuits and reverse set of circuits, and the follower device being adapted to be moved upon establishment of one of said cir cuits a distance from neutral position sufficient to break the circuit and reestablish neutral conditions, the setting of the pre-set device in either direction determining the distance of movement of the follower device in that direction required to break the circuits, a forward first circuit through the pre-set device set in one direction to cause operation of the motor in a forward direction, a reverse first circuit through the pre-set device set in the other direction to cause opera tion of the motor in the other direction, forward operating means to operate the follower device to displace the same in forward direction toward position to break the circuits, reverse operating means to operate the follower device to displace the same in reverse direction toward position to break the circuits, a motor switch means made and broken in a cycle a predetermined number of times per revolution of the motor, a second forward circuit controlled by the first forward circuit and including the forward operating means and the motor switch, and a second reverse circuit controlled by the reverse first circuit and including the reverse operating means and the motor switch, whereby upon operation of the pre-set device in either direction the motor will start in a corresponding direction, and the follower will be successively moved toward circuit breaking condition a predetermined degree for each revolution of the motor, means on each operating means to shunt the pre-set device in the corresponding first circuit when the corresponding operating means is in operated position, and means to prevent closure of one first circuit when the other operating means is in operated position, and means to release the operated means from operated position when the motor circuit is opened, comprising a relay coil in the motor circuit and a switch operated thereby in series with the motor switch.

11. In a mechanism of the kind described, a motor, a preselector device displaceable from a neutral position selectable distances, a circuit established through said preselector device only when it is out of neutral position, a power. relay coil in said circuit, a relay switch means operated by said coil, a second circuit through said relay switch means to the motor, a control operating relay, a switch cycled a predetermined number of times for each revolution of the motor, a third circuit including the relay switch when the relay is operated, the control operating coil and the motor switch, said third circuit being adapted to be made and broken during each cycle of the motor switch, a switch closed by the control relay, and a shunt circuit for the power relay closed by said last named switch, said shunt circuit shunting the preselector means from the power relay circuit, and means operated by said control relay and movable with respect to the preselector means toward neutral position a predetermined distance for each operation of said relay.

12. In a mechanism of the kind described, a reversible motor, a shaft rotated thereby, a switch cycled from the shaft a predetermined number of times per revolution of the shaft, a pair of limit switches, the first operated after a certain number of revolutions of the motor in one direction and the other operated after a certain number of revolutions of the motor in the other direction, a control device including a selectively displaceable device and a follower, the follower being adapted to assume a neutral position relative to the displaceable device and adapted to be moved in either direction relative to said device, circuit making means including the device and the follower when not in neutral position, a forward and a reverse power relay, a forward and a reverse second stepping relay, each relay in cluding switch means operated from a first to a second position upon energization of the said relays, a forward first circuit through the circuit making means, the second stepping relay switch in first position, the first power relay coil, to ground, a forward second circuit established upon energization of the first power relay through its switch in second position through a forward limit switch through the motor in one direction, through the reverse limit switch, through the second power relay switch in first position, to ground. a third forward circuit through the first power relay switch in second position, through the first stepping relay coil, and through the motor switch to ground, whereby the first stepping relay is operated to second position, a shunt circuit through the first stepping relay in second position, the first power relay coil to ground, and means operated by the stepping relay coil to move the follower toward neutral position a predetermined distance for each energization of said relay coil, and symmetrical reverse circuits corresponding to said forward circuits.

13. In a mechanism of the kind described, a reversible motor, a shaft rotated thereby, a switch cycled from the shaft a predetermined number of times per revolution of the shaft, a pair of limit switches, th first operated after a certain number of revolutions of the motor in one direction and the other operated after a certain number of revolutions of the motor in the other direction, a control device including a selectively displaceable device and a follower, the follower being adapted to assume a neutral position relative to the displaceable device and adapted to be moved in either direction relative to said device, a circuit making means including the device and the follower when not in neutral position, a forward and a reverse power relay, a forward and a reverse sccond stepping relay, each relay including switch means operated from a first to a second position upon energization of the said relays, a forward first circuit through the circuit making means, the second stepping relay watch in first position, the first power relay coil, to ground, a forward second circuit established upon energization of the first power relay through its switch in second position through a forward limit switch through the motor in one direction, through the reverse limit switch, through the second power relay switch in first position, to ground, a third forward circuit through the first powerrelay switch in second position, through the first stepping relay coil, and through the motor switch to ground, whereby the first stepping relay is operated to second position, a shunt circuit through the first stepping relay in second position, the first power relay coil to ground, and means operated bythe stepping relay coil to move the follower toward neutral position a predetermined distance for each energization of said relay coil, the forward limit switch being adapted to connect its end of the motor circuit to ground, means to break the third circuit, to release the operating means, and symmetrical reverse circuits corresponding to said forward circuits.

14. In a mechanism of the kind described, a reversible motor, a shaft rotated thereby, a switch cycled from the shaft a predetermined number of times per revolution of the shaft, a pair of limit switches, the first operated after a certain number of revolutions of the motor in one direction and the other operated after a certain number of revolution of the motor in the other direction, a control device including a selectively displaceable device and a follower, the follower being adapted to assume a neutral position relative to the displaceable device and adapted to be moved in either direction relative to said device, a circuit making means including the device and the follower when not in neutral position, a forward and a reverse power relay, and forward and a reverse second stepping relay, each relay including switch means operated from a first to a second position upon energization of the said relays, a forward first circuit through the circuit making means, the second stepping relay switch in first position, the first power relay coil, to ground, a forward second circuit established upon energization of the first power relay through its switch in second position through a forward limit switch through the motor in one direction, through the reverse limit switch, through the second power relay switch in first position, to ground, a third forward circuit through the first power relay switch in second position, through the first stepping relay coil, and through th motor switch to ground, whereby the first stepping relay is operated to second position, a shunt circuit through the first stepping relay in second position, the first power relay coil to ground, and means operated by the stepping relay coil to move the follower toward neutral position a predetermined distance for each energization of said relay coil, the forward limit switch being adapted to connect its end of the motor circuit to ground, means to break the third circuit, to release the operating means, and symmetrical reverse circuits corresponding to said forward circuits, said breaking means com-prising a relay coil in the motor circuit and a switch operated thereby in series with the motor switch.

CLINTON I-I. DEDER'ICK. 

